文献类型：期刊文献

英文题名：Citric Acid-Mediated Dealumination of HY Zeolite for Enhanced Isopropylation of Naphthalene to 2,6-Diisopropylnaphthalene

作者：Wang, Xin[1];Ju, Ziying[1];Li, Wanchun[1];Xiao, Kexin[1];Meng, Xuan[1];Liu, Naiwang[1]

机构：[1]East China Univ Sci & Technol, Shanghai 200237, Peoples R China

年份：2026

卷号：603

外文期刊名：MOLECULAR CATALYSIS

收录：;EI(收录号：20263421346134);Scopus(收录号：2-s2.0-105047854776);WOS:【SCI-EXPANDED(收录号:WOS:001856983900001)】；

语种：英文

外文关键词：HY zeolite; 6-DIPN; alkylation; naphthalene

摘要：2,6-Diisopropylnaphthalene (2,6-DIPN) is a critical precursor for high-performance polymers. However, its synthesis via naphthalene isopropylation over HY zeolites is often limited by suboptimal selectivity and a susceptibility to coke deactivation, primarily due to restricted diffusion and uneven acid distribution. Herein, commercial HY zeolite was treated with aqueous citric acid solutions of different concentrations at 80 degrees C, followed by washing, drying, and calcination, to regulate its pore structure and acidic microenvironment. Under the initial test conditions (180 degrees C, 0.7 MPa propene, 7 h), the naphthalene conversion and 2,6-DIPN selectivity over the 0.1 mol & sdot;L-1 citric acid-modified HY zeolite were 97.65% and 29.55%, respectively. Upon further condition optimization (180 degrees C, 0.7 MPa, 5 h), the 0.1 CA-HY catalyst delivered optimal performance, achieving a naphthalene conversion of 97.37% while increasing the 2,6-DIPN selectivity to 34.6%. Comprehensive characterizations indicate that mild citric acid treatment modifies the aluminum coordination environment and promotes the removal of accessible aluminum-containing species, accompanied by the formation of a secondary mesoporous network. This hierarchical structural evolution effectively enhances the spatial accessibility of Br & Oslash;nsted acid sites and optimizes the Br & Oslash;nsted/Lewis (B/L) acid ratio. Furthermore, the 0.1 CA-HY catalyst exhibits favorable regenerability, retaining over 90% of its initial activity following a facile thermal treatment. This strategy provides a viable approach to balance micropore shape selectivity, mesopore mass transfer, and acidity regulation, presenting a promising catalytic system for arene alkylation.